The invention relates to a device comprising a movably mounted member for transferring a film from a backing tape onto a substrate.
A hand-held device for applying a film from a backing strip onto a substrate is described in EP 0 575 790 B1 (corresponding to U.S. Pat. No. 5,346,580 to Eldges et al.). In this known device a supply reel and a take-up reel for a backing tape and a spatula-shaped application member are mounted on a cassette which can be pushed into a housing through an opening from the rear. A use position and a non-use position for the cassette unit are provided. In the use position, the application member projects out of the housing so that it can be pressed against a substrate to transfer a film onto the substrate. In the non-use position, the application member is arranged in a recessed position in the housing. In this position, both the application member and the backing tape plus film running around the application member are protected against damage caused by other equipment which is almost impossible to prevent during handling at a workplace. In this known device, the cassette unit is secured in the use position of the application member against displacement in either displacement direction. In the non-use position, the cassette unit is prevented from being displaced backwards. This arresting movement is performed by a spring arm arranged on the cassette unit which comprises a push button with two push button stages arranged offset from each other in the longitudinal direction. The first push button stage projects through a through-hole in the housing in the use position and the second push button stage projects through the through-hole in the housing in the non-use position. The push button stages can be accessed from the outside by a finger of the user""s hand through the through-hole. To displace the application member from its use position into its non-use position, the first push button stage has to be pressed inwards out of its latched position in the through-hole with manual pressure from outside, causing the cassette unit to be moved automatically into its non-use position by a pull-back spring where the second push button stage automatically locks it into place as a result of the spring force of the spring arm. The application member is moved from its non-use position into its use position by means of manual pressure on the rear end of the cassette unit which projects rearwards out of the housing and is therefore manually accessible. In the case of such a displacement into the use position, the first push button stage automatically engages in the through hole.
This known device is detrimental for several reasons. First, the device requires manual activation of a push-button to initiate displacement of the application member into its non-use position. It is easy for impact damage to be caused to the film in the projecting portion of the application member during handling in the workplace, it becomes clear that the application member has to be manually displaced into its non-use position relatively often, constituting considerable handling effort and demanding the person using the device pay close attention.
Another disadvantage of this known design lies in the fact that the application member extends axially relative to the longitudinal middle axis of the elongated or pen-shaped housing and can also be moved axially. This makes for an inopportune position of the device during handling.
A further drawback of the known device is that the known construction is only suitable for a device which has the reels and the application member arranged on an insert cassette. This known construction cannot be used in a device which has the application member and the reels mounted directly on the housing.
The fact that axial transverse force has to be exerted at the rear end of the device to move the application member into its use position is also to be regarded as a drawback of this known device. To do so, the device has to be gripped in a particular manner by both operating hands and subjected to a transverse force.
The present invention facilitates and improves the handling of a device for applying a film from a backing to a substrate (alternately referenced herein as an applicator device for the sake of convenience without any intent to limit) in its operating mode. This functioning should be at least partially automated or mechanized and it should be possible to perform or initiate the respective functions with user-friendly handling and operations. Furthermore, the device should be formed such that it is also possible to shift the application member between a retracted or submerged non-use position and a protruding use position even if there is no insertion cassette available, that is when the application member and the reels are mounted on the housing.
Backwards movement of the application member from its use position into its non-use position is effected automatically when the application member is removed from the substrate, or when the force with which the application member is pressed against the substrate or with which the actuation member is moved falls below a certain value, e.g., is no longer maintained, or when the manual operation of an actuation member for moving the application member into its use position is ended. The invention is based on the realization that the force with which the application member is pressed against the substrate during transfer of a film or the actuating force can be exploited to keep the application member in its use position, and to activate a preferably available positioning device for the application member which loses its function when the above-described features of the invention are realized. During handling of the device, the housing is to be held in a certain working position relative to the substrate and the actuation member is to be moved which, when manually grasping the device, can however occur at the same time and can therefore happen in a user-friendly manner with just one operating hand.
It is advantageous to provide the application member with a stopping face in the use position which restricts the movement of the application member into the non-use position during pressing onto the substrate or during the exertion of actuating force. This makes handling even simpler and relieves the user""s hand to actuate the actuation member because the stopping surface introduces the majority of the pressing force into the housing without the user""s hand having to counteract the thrust resulting from the pressing force by actuating or moving the actuation member.
It is also advantageous to bear the application member such that it is movable or swivellable transversely to its main direction of movement stretching between the use position and the non-use position. As described above, the pressing force can be used to move the application member transversely into a positioning position, e.g., against the stopping surface in which position it is positioned relative to a backwards movement. When the pressing-exerting force and/or actuating force is reduced or stopped, or the device is lifted from the substrate, the backwards movement of the application member and its movement into the non-use position can then also be effected automatically. In doing so, it is advantageous to generate each of these movements with elastic force or a common elastic force which is well suited for the automatic or self-acting backwards movement of the application member into its non-use position. The stopping surface can be formed by a guiding surface pointing laterally towards the front end of the application member and the application member can comprise a shoulder surface pointing away from its front end with which it is moveable, in particular swivellable, in the backing tape deflecting plane into a position interacting with the guiding surface. In this design, the application member can, in its use position, be subjected to a transverse movement to bring it into a stopping position with the guiding surface, which forms a stop against pull-back movement of the application member. This makes handling considerably simpler because the operating hand can transfer the pressure onto the application member indirectly over the housing rather than directly.
The handling of the applicator device of the present invention is also simplified for ergonomic reasons. This is conditioned by the fact that the application member is positioned favorably relative to the substrate in a normal workplace when the device is held comfortably in the operating hand. In this position, the necessary pressure required for transferring the film can be applied in a user-friendly manner. A further advantage of this embodiment is that an actuation member for moving the application member into its use position can be arranged in a simple and ergonomically favorable way in the front portion of the top side of the device. In such an arrangement, the pushing out movement of the application member and the actuation member can be exploited to exert the pressure directly, the actuation member being used as an abutment on which, for example, a finger of the operating hand can apply the pressing force in a user-friendly manner.
The invention is also based on the object of improving the backing tape guidance or the deflection around the application member in an applicator device, especially during shifting of the application member between its non-use position and its use position.
The backing tape is guided closely about the front end of the application member with contact thereto in both positions of the application member. In this embodiment, guidance of the backing tape in the moving section of the application member is guaranteed, thus preventing defects being caused by loops forming.
In an arrangement guiding the movement of the application member on the housing, this embodiment can also be realized without providing a cassette unit for the application member and the reels. In this embodiment, it is beneficial for the backing tape to form a substantially closed loop in its course about the application member. This enables the loop to adapt to the positional changes of the application member when the movement of the application member changes. Furthermore, it is beneficial for the application member and its direction of movement to extend transversely to the middle axis of the loop. This has a favorable effect on the changes in the course of the backing tape during movements of the application member and difficulties regarding a loss of guidance for the backing tape, and start-up problems during transfer of the film from the backing tape to the substrate can be avoided.
The further embodiments contain features which lead to small and functioning designs which can be beneficially integrated in the device and also allow production at reasonable costs.